A type of drilling unit known as a blast hole drill is used in surface mining and quarrying operations. The unit is typically mobile, being mounted on a vehicle that travels on wheels or tractor crawlers. Blast hole drills and other similar drilling rigs use drill pipe strings that are made up of drill pipes that are threaded end to end. The first pipe, i.e. the first pipe entering the hole being drilled, in the drill pipe string has an upper end connected to the next pipe in line and a lower end, on which a drill bit is mounted.
The drill bit is typically threadably connected to the lower end of the first pipe and after a period of use becomes dull due to the constant wear of the drilling operation. As a result, the drill bit must be replaced on a regular basis in order to quickly and efficiently drill holes. Replacement of the drill bit is a time consuming operation requiring workers to manually remove the used drill bit and mount a new drill bit onto the lower end of the first pipe. A need exists for an improved method and equipment that simplifies changing out these drill bits.